microswitch was mounted on the yoke lever, which allowed 

 the reversing motor to be energized only when the indexing 

 yoke was lifted clear of the rack. 



THERMAL SYSTEM 



To maintain the calibration tank at a constant 

 temperature below ambient, an auxiliary thermal system 

 (fig. 5) pumps refrigerated water into it in quantities 

 sufficient to offset its natural rise in temperature toward 

 that of the room. To maintain its temperature above 

 ambient, the auxiliary system pumps heated water into it 

 to cancel the effect of heat loss. The water injection is 

 automatically regulated by solenoid valves which are 

 controlled by a thermal sensor in the calibration tank. 



FILTER BYPASS VALVE FILTER BALL VALVES 



NEEDLE 



VALVES 



RETURN LINE 



FULL FLOW 

 FILTER 



HOT TANK 



COLD TANK 



THERMOSTAT 

 (HOT TANK) 



HEATING 

 ELEMENTS 



THERMOSTAT 

 COLD TANK) 



SOLENOID 



VALVES 

 HOT 

 COLD 



BALL VALVES 

 Figure 5. Auxiliary thermal system (hot and cold tanks). 



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